This invention refers to a method and an installation for carrying unstable containers such as bottles and the like, (namely slight containers having a small supporting bottom) said containers being positioned with a predetermined, generally upright, orientation by means at least of one automatic positioning machine, well-known in itself, as disclosed in U.S. Pat. No. 4,681,209 and EP 0432081 owned by the applicant. Said positioning machines are designed for supplying, aligned and uprightly oriented containers, such as plastic bottles, by means of a conveyor belt which transfers them to a treatment station, for example a labelling, filling etc. station and they are only fit in principle to treat flat bottom containers, of a sufficiently large size.
In the patent ES 8609116 an alternative is proposed to treat by means of machines of the above type, containers having a bottom which is not flat, which consists in an overhead carrier which picks up containers by their neck between two coplanar roll-on belts. Although this solution provides good results it demands the use of a non-standard conveyor along the whole container supplying line.
In order to achieve the container's supply by means of a standard conveyor, the method according to the invention proposes the use of some auxiliary elements, to house the containers during their carriage, such as empty pucks having a large bottom.
The idea of using pucks having a stable bottom fit to house the containers for their transfer, loaded within said pucks, in an in-line production equipment is disclosed in U.S. Pat. No. 3,941,237 and U.S. Pat. No. 3,090,478, document U.S. Pat. No. 4,305,496 discloses a method to carry a plurality of single containers 18 from a centrifugal rotating feeder 20 to a position in which said containers are left to drop in respective pucks 12 in a loading area. Containers 18 are oriented by a centrifugal rotating feeder 20 and fed to notches 22 provided on the periphery of said centrifugal feeder 20, being supported at the lower end by an arcuate-sector-shaped fixed floor 26 under feeder's 20 periphery. Under said floor 26 a plurality of empty pucks 12 are fed by a conveyor 28 and through an endless rotating belt 10 and an arcuate handrail 30 sector up to a loading area where empty pucks collect containers 18 and from there onward they travel on a circular path up to an unloading area approximately opposite to the filling or loading area. supporting fixed floor 26 extends only in part under feeder's 20 peripheral area in order that the end thereof (FIG. 6 and 9), at dropping area, containers 18 pass outside plane 26 and within pucks openings on conveyor belt 10 along dropping area and up to unloading area where loaded pucks are shifted from element 10 and guided up to an outlet endless conveyor 36 by a deflector bar 32. Empty pucks go on their way on conveyor belt 10 on a circular path to go back to the feeding area.
But in this background of U.S. Pat. No. 4,305,496, no solution is provided or even suggested to the problem of linking recirculated empty pucks to empty pucks which arrive to the loading area fed by conveyor 28 and this is evidenced because in a second further patent of same applicant, U.S. Pat. No. 4,723,661 referring to a mechanism to achieve said method, a very complex, expensive and bulky plant to reach such aim is disclosed. Another problem, not considered by said two backgrounds is to guarantee that on the area where the containers fall from the centrifugal feeder fixed supporting plane, said containers adopt a specific position in order to be coincident with the openings provided in the pucks, which is especially important in the event of flat containers such as flattened plastic bottles.
In addition, said two patents, U.S. Pat. No. 3,941,237 and U.S. Pat. No. 3,090,478, start from the principle of carrying said empty pucks to a meeting point with a positioning machine, from which containers are transferred to the interior of said pucks.